Traditionally, many surgical procedures have been performed on patients using open surgical methods that utilize relatively large incisions to expose a surgical field. Many traditional methods have also typically utilized surgical tools such as scalpels, scrapers, blunt dissectors, lasers, electrosurgical devices, etc., which have poor tissue differentiating capability and which can easily cause inadvertent damage to tissue surrounding a surgical treatment site unless carefully utilized. Open surgery with such prior art surgical instruments often involves extensive trauma to the patient, with associated problems of long recovery periods and potential complications.
There has been a trend in recent years to perform many surgical procedures using less invasive techniques by accessing surgical sites via small holes through the skin or through body orifices. These techniques are known as “minimally invasive surgery.” Minimally invasive surgical techniques commonly employed include endoscopic, laparoscopic, and arthroscopic surgical procedures. Minimally invasive surgical procedures are commonly preferred to open surgical procedures for many applications because the minimally invasive procedures induce less trauma to the patient during surgery and involve, in many cases, fewer potential complications and reduced recovery time.
A variety of instruments have been developed and utilized for minimally invasive surgical procedures. Frequently used instruments include blades and scalpel-type instruments, motorized rotary blade instruments, laser instruments, and electrosurgical or electrocautery instruments. Typically, these prior art instruments suffer from a variety of disadvantages. For example, the instruments can be slow and laborious to use, typically they lack the ability to selectively differentiate tissue to be excised from non-target tissue, they tend to have sizes and/or shapes which make access of many surgical sites difficult, and they tend to cause unintended damage to tissue surrounding the intended target tissue. Most prior art instruments also require the operator to manually remove excised tissue, for example with forceps, or require an external source of vacuum to be applied to the surgical site, for example via an aspiration tube that is separate from the surgical instrument, in order to remove excised tissue. For applications such as arthroscopy, where visualization of the surgical site is typically effected using an imaging system having a probe such as a fiber optic probe inserted into the surgical site, the above mentioned prior art surgical instruments also typically make it difficult to clearly visualize the site of tissue excision within the surgical field by not effectively evacuating tissue and debris from the surgical site.
Instruments that employ liquid jets have also been utilized in surgical procedures for cutting and ablating tissue. Such instruments have many advantages over the above mentioned surgical instruments for performing both open and minimally invasive surgical procedures. For example, the cutting or ablating power of the liquid jet may be adjusted or controlled by an operator of the instrument, for example by varying the pressure of the liquid supplied to form the jet, to allow for improved tissue differentiation and to reduce inadvertent damage to surrounding tissues when cutting or ablating the target tissue. Liquid jet instruments also can avoid the thermal damage to surrounding tissues that is often caused by instruments such as lasers and electrosurgical devices. In recent years, liquid jet instruments have been utilized for a variety of surgical procedures including open surgical procedures such as liver resection, endoscopic procedures such as kidney stone disruption and removal, and arthrectomy procedures for removal of thrombotic tissue from the vascular system.
U.S. Pat. No. 4,898,574 to Uchiyama et al. describes a variety of lithotomic devices for insertion into a body cavity, which create a fluid jet that is utilized to break up and crush calculi, for example kidney stones, in the body of a patient. The instruments disclosed typically include one or more suction channels for removing fluid and debris. The instruments require that the suction channel be coupled to an external source of vacuum, such as a vacuum pump. The instruments disclosed also typically lack a target or deflector upon which the fluid jet impinges, and, therefore, have the disadvantage of potentially causing unintended damage to healthy tissue by misdirection of the fluid jet.
U.S. Pat. No. 4,913,698 to Ito et al. describes a liquid jet surgical handpiece designed for crushing and removing brain tumors in cerebral surgery. The disclosed instrument includes a liquid jet forming nozzle and a suction tube, which is required to be coupled to an external source of vacuum for removal of the tissue and debris excised by the liquid cutting jet. The liquid jet nozzle is oriented in such a manner that the liquid jet from the nozzle is directed towards a confronting inside wall of the tip of the suction tube when the instrument is in operation in order to prevent the liquid jet from inadvertently damaging a non-target tissue.
U.S. Pat. No. 5,135,482 to Neracher discloses a liquid jet instrument for removing a deposit obstructing a vessel in a human body. The device is configured as a multi-lumen catheter, which includes a pressure resistant duct having a nozzle orifice that creates a supersonic cavitating liquid jet. The liquid jet is directed distally from the instrument to ablate a deposit within a vessel. Some embodiments of the catheter device also include a suction lumen which can be coupled to an external source of vacuum for removing liquid and debris from the vessel. The catheter instruments disclosed do not include a deflector or target element to prevent the liquid jet from potentially impinging upon and causing unintended damage to the vessel or tissue surrounding the deposit to be ablated.
U.S. Pat. No. 5,318,518 to Plechinger et al. disclose a fluid jet instrument configured as a catheter for ablation and removal of a material or deposit from a body vessel or hollow organ. The distal end of the catheter includes a fluid jet nozzle that directs a fluid jet into the mouth of a discharging lumen when the instrument is in operation. The discharging lumen includes a mixing tube and diffuser element. The fluid jet directed into the discharging lumen creates an aspiration force, due to eductor pump action, which serves to transport fluid and ablated material through the discharging lumen without the need for an external source of suction. The mixing tube and diffuser element included in the discharging lumen serve to enhance the aspiration force created by the eductor pump action. The fluid jet can shred or shatter tissue or deposits that lie between the nozzle outlet and the inlet of the discharging lumen, and can drive the shattered particles into the inlet of the discharging lumen for evacuation from the surgical site.
U.S. Pat. No. 5,370,609 to Drasler et al. discloses a fluid jet thrombectomy catheter for removing a thrombus deposit from the cardiovascular system of a patient. The catheter includes a pressure lumen for transporting a high pressure liquid to at least one jet nozzle, and a relatively large bore evacuation lumen for removing liquid and ablated tissue and debris. In operation, the catheter is configured to direct at least one liquid jet into the opening of the large-bore evacuation lumen in a direction that is proximal and coaxial with the evacuation lumen. By directing the jet towards the orifice of the large-bore evacuation lumen of the catheter, a stagnation pressure is induced which can propel fluid and debris proximally for removal.
U.S. Pat. No. 5,527,330 to Tovey discloses a fluid jet cutting and suctioning instrument configured, in some embodiments, for laparoscopic insertion into a patient through a trocar. The instrument includes a body having a handle, an irrigation tube that includes a fluid jet nozzle at its distal end, and an evacuation tube, or in some embodiments a backstop member, positioned to receive the fluid jet. Several of the disclosed embodiments involve an instrument for creating a fluid jet that is directed transversely to a longitudinal axis of the body of the instrument. In one embodiment, the instrument includes a sliding sheath element that is able to move the irrigation tube and suction tube laterally with respect to each other to adjust the gap between the fluid jet forming nozzle and the inlet of the suction tube so as to change the length of the fluid cutting jet, when the instrument is in operation. The instruments described by Tovey have several disadvantages for use in many minimally invasive surgical procedures. For example, the shape and design of the irrigation and suction tubes requires the instrument to be relatively bulky and have a cross-sectional dimension and shape that is ill suited for inserting the instrument into confined regions of the body for performing many minimally invasive surgical procedures. In addition, the instruments disclosed are designed so that an external source of suction must be coupled to the suction tube in order to evacuate fluid and ablated tissue from the surgical site.
While the above mentioned surgical liquid jet instruments represent, in some instances, significant improvements over many prior art surgical instruments for performing open and minimally invasive surgical procedures, there remains a need in the art to provide simple, inexpensive, liquid jet surgical instruments which have improved cutting, ablation, and tissue evacuation capabilities, and which have the ability to be utilized in a wide variety of open and minimally invasive surgical procedures. The present invention provides, in many embodiments, such improved surgical liquid jet instruments, and further provides methods for their use in a variety of surgical procedures.